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Windows 11 24h2Operating system · Microsoft

CVE-2026-42910

HIGH · 7.8 CVSS v3.1 Published 2026-06-09
Fix available
A fix is available. Upgrade to 10.0.26100.8655 / 10.0.26100.32995 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Out-of-bounds write in Windows Hotpatch Monitoring Service allows an authorized attacker to elevate privileges locally.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

This is a local privilege escalation vulnerability in the Windows Hotpatch Monitoring Service. The flaw is an out-of-bounds write vulnerability that allows an authenticated local attacker to write beyond allocated memory boundaries, potentially overwriting sensitive memory locations to elevate their privileges from a standard user to higher-level SYSTEM or administrator privileges.

MitigationApply the relevant Microsoft Windows security update for this CVE. As a local privilege escalation, ensure least-privilege principles are enforced and monitor for suspicious local access attempts until patching is complete.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Windows 11 24h2Operating system
Affected:< 10.0.26100.8655
Windows 11 25h2Operating system
Affected:< 10.0.26200.8655
Windows 11 26h1Operating system
Affected:< 10.0.28000.2269
Windows Server 2025Operating system
Affected:< 10.0.26100.32995

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Windows version and build number
    Run `winver` or execute `systeminfo | findstr /B /C:"OS Name" /C:"OS Version"` in Command Prompt, or use PowerShell: `Get-ComputerInfo | Select-Object WindowsProductName, WindowsVersion, OsHardwareAbstractionLayer`
    Affected if The build number is less than 26100.8655 for 24h2, less than 26200.8655 for 25h2, less than 28000.2269 for 26h1, or less than 26100.32995 for Windows Server 2025
  2. Identify the Hotpatch Monitoring Service
    Open Services (services.msc) and look for a service named "Hotpatch Monitoring Service" or run PowerShell: `Get-Service | Where-Object {$_.DisplayName -like "*Hotpatch*"}`
    Affected if The Hotpatch Monitoring Service is present on the system (note: this service may not be visible on all Windows editions)
  3. Check if the service is running
    If the Hotpatch Monitoring Service is found, run `Get-Service -Name "ServiceName"` in PowerShell or check the Status column in Services.msc
    Affected if The service is installed and running (the vulnerability requires the service to be active for exploitation)

You are affected if your Windows build number falls within the affected version ranges AND the Hotpatch Monitoring Service is present and running on your system.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 10.0.26100.8655 / 10.0.26100.32995 / 10.0.26200.8655 or later
Fixed in 10.0.26100.865510.0.26100.3299510.0.26200.8655
Interim mitigation

Apply the relevant Microsoft Windows security update for this CVE. As a local privilege escalation, ensure least-privilege principles are enforced and monitor for suspicious local access attempts until patching is complete.

Recommended fix High confidence

Windows 11 24h2 build 10.0.26100.8655 or later | Windows 11 25h2 build 10.0.26200.8655 or later | Windows 11 26h1 build 10.0.28000.2269 or later | Windows Server 2025 build 10.0.26100.32995 or later

  1. Check current Windows build version by running 'winver' or 'systeminfo | findstr /B /C:"OS Version"'
  2. Open Windows Settings and navigate to Windows Update > Check for updates, or use WSUS/SCCM to deploy updates
  3. Install all available security updates for your Windows version (the fix is included in the KB for the month of the CVE release)
  4. Restart the system after the update is applied
  5. Verify the fix by running 'winver' and confirming the build number meets or exceeds: Windows 11 24h2: 10.0.26100.8655, Windows 11 25h2: 10.0.26200.8655, Windows 11 26h1: 10.0.28000.2269, Windows Server 2025: 10.0.26100.32995
Caveat Standard Windows security update risks apply - test in non-production environment first, ensure backups exist before updating

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Windows 11 24h2 Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA2.0 h
8.0 hours of engineering $1,390
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,224.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-42910 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data